Charles Kennedy's distinctive position in opposing the Iraq war has given the Liberal Democrats a unique selling point among the main parties.
His anti-war stance has won the Liberal Democrats a boost in the polls and two by-election victories at Labour's expense and there is little sign that the issue of Iraq will fade as the parties move on to a general-election footing.
But yesterday Mr Kennedy took his opposition to the war in Iraq one step further by declaring that he would not allow increased fears about insecurity on the international stage to erode "hard won" civil liberties in Britain.
Mr Kennedy remarked how striking it was that "the international situation is continuing to shape the domestic agenda" and then stepped perilously close to accusing the Government of manufacturing "a climate of fear" as an excuse to clamp down on basic freedoms.
In the next session of Parliament - probably the last before the next general election - the Liberal Democrats would lead the opposition to "repressive measures", such as ID cards, the party leader said. His pledge represents a significant shift back on to Liberal territory for the party. When Mr Kennedy took over as leader, there were mumblings that he would seek to shift the party away from the Liberal ideals of his predecessors.
So it may have come as a surprise to some to see Mr Kennedy, who entered political life as an SDP MP, flanked by Lord McNally, who is also a former SDP MP, leading the attack on government "illiberalism" yesterday.
In pledging to oppose "authoritarian measures which restrict our personal freedom" he set down a marker that his party's Liberal roots would not wither and die in his charge.
The move was also strategically clever and put the Tories, who have claimed political ownership of the agenda of individual freedom, on the back foot.
The Liberal Democrats' alternative Queen's Speech included policies designed to appeal across the political spectrum and to all age groups and it showed Mr Kennedy is not afraid to exploit the "trust" factor which has been dogging Tony Blair.
By promising to scrap university tuition fees, Mr Kennedy appeals to students and parents feeling the pinch from the cost of higher education.
The elderly will warm to pledges to boost pensions, restore free personal care and replace the council tax with a local income tax. The party's ambitious programme on the environment makes government claims to be green look hollow.
But yesterday the Liberal Democrats faced questions once again from Labour and the Tories about how they would pay for their ambitious proposals - despite presenting the most carefully costed agenda for decades.
As the Liberal Democrats become a more credible electoral prospect, they will come under ever closer scrutiny from their opponents. Yet there are some troubling gaps in the party's policy agenda, which need to be plugged before the general election. Mr Kennedy's task in the coming months will be to ensure that his programme stands up to such rigorous attention.